Mounting devices to surfaces that are, or maybe, exposed to unpredictable and varying force vectors caused by wind, rain, and other elements of weather present technical problems often difficult to solve. A long standing and unsolved challenge in the solar energy industry, for example, has been resolving how best to mount panels, modules and arrays of photovoltaic devices (collectively, “module” or “modules”) on surfaces not only securely and safely, but also quickly. The obverse problem also is significant to the industry, namely safely removing or reconfiguring a module that has been installed on a surface.
Solar energy radiation from the sun is capable of producing heat, causing chemical reactions, or generating electricity. The sun is an extremely powerful energy source, and solar radiation is by far the largest source of energy received by Earth, but its intensity at the Earth's surface is comparatively low. This is partly because Earth's atmosphere and its clouds absorb or scatter as much as 54 percent of all incoming sunlight. Solar energy, however, due to technological improvements in the manner of collecting the potential energy, has become increasingly attractive as an energy source: it is inexhaustible in supply, and non-polluting, both in stark contrast to fossil-fuel sources like coal, oil, and natural gas.
Sunlight reaching earth consists of approximately 50 percent visible light, 45 percent infrared radiation, and small amounts of ultraviolet light and other forms of electromagnetic radiation. Radiation is convertible either into thermal energy or directly into electricity by photovoltaic cells. In photovoltaic cells, a small electrical voltage is generated when light strikes the junction between a metal and a semiconductor or a junction between two different semiconductors. Although the voltage generated from a single photovoltaic cell typically is only a fraction of a volt, by connecting large numbers of cells together into panels, modules and arrays, significant electric power can be generated. To harness radiation for direct generation of electricity using cells collected into panels, modules and arrays, a number of apparatus and methods for using and installing the apparatus have been devised on which to mount modules on surfaces exposed to the radiation. The construction, installation, and use of such apparatus present a number of unsolved problems.
A wide variety of racks, frames and associated hardware have been proposed to mount modules on surfaces. Some solutions have proposed modifications of the shape, structure and size of components of a module to achieve more rapid and secure mounting. Other solutions have proposed altering the construct and design of hardware associated with installing racks, framing, and footings into a footing grid on which modules are mounted. As used in this document the term “footing grid” includes a network of keepers often, but not exclusively, L-shaped and formed with at least one hole in each extension of the “L.” The keepers are connectable to a surface and are formed and shaped to permit attachment of other hardware components such as rails and frames on which modules may be attached.
Prior approaches suggested for mounting a module on a surface include significant limitations and problems. A serious challenge to providing a useful apparatus and method for mounting a module on a surface arises from the variety of sizes and shapes of the modules, as well as the varying number of modules that might be required in a given situation. Another challenge that earlier suggestions did not overcome is the variety of surfaces on which modules may or must be mounted, including roofs, tops and sides of poles, the ground, and other locations. Many earlier solutions, therefore, required construction of custom built racks to fit each of the enumerable iterations of the sizes and shapes of modules.
Many earlier suggestions for mounting panels, modules and arrays of photovoltaic devices on surfaces are cumbersome, unsafe, and not easily assembled or reconfigured. Also, none of the solutions provided an apparatus, and method for installing the apparatus, that would be universal. The term “universal” refers to an apparatus and method for mounting modules on a wide variety of surfaces that not only accommodate all known shapes, configurations, and numbers of modules, but also permit installation top down as well as bottom up. In the industry associated with installation of photovoltaic modules, the term “top down” refers to mounting photovoltaic modules on structures such as frames and rails that are attached first to the footing and on the surface on which the module is to be mounted before the module is attached to the frames or rails. For example, in the case of a module to be mounted on a building, one or more rails first would be attached to a footing grid that earlier has been attached to the surface, in this instance the roof; thereafter, one or more modules would be attached to the rails. Hardware that secures the module to the rails is attached from the top, or front, of the module. The term “bottom up” refers to positioning a photovoltaic module by first attaching the module to the footing grid and to the roof or other surface. In bottom up mounting, hardware used to secure the module to the rail is attached from the bottom or back of the module. The uniqueness of each installation, an installer's preferences, and the particular module all will determine whether a top down or bottom up installation is used. Significantly, none of the currently available apparatus for mounting photovoltaic modules to a surface allow installation both top down and bottom up using the same rail system.
Another limitation of current approaches for mounting photovoltaic modules to a surface is the excessive number and variety of hardware parts and components that are required to assemble a frame or rail system. Each module or combination of modules installed may present different shapes, sizes and configurations, thus requiring a unique combination of mounting hardware.
Still another unresolved problem arises from the varying shapes, sizes and configurations of modules. The arrangement of the modules on a surface such as a roof may not be dimensionally consistent with the location of rafters underneath the roof into which hardware must be inserted to hold the footing grid and rails.
Still another limitation of present apparatus for assembling and mounting modules on surfaces is the absence of a system and apparatus that permits easily adjusting and readjusting of the location on a rail on which the module may be positioned.
Therefore, a previously unaddressed need exists in the industry for a new and useful system for positioning a device such as a photovoltaic panels, modules and arrays of photovoltaic devices on a surface such as a roof, pole or other surface. Particularly, there is a significant need for a method and apparatus for mounting one or more photovoltaic modules safely, reliably, yet quickly on a surface; removing or reconfiguring the modules just as safely, reliably and quickly; and providing a system that is adjustable and expandable to allow a variety of dimensions and configurations.